The present invention pertains to printing apparatus having replaceable modules, and the replacement of replaceable modules of a printing apparatus. In particular, the present invention pertains to avoiding contamination of or damage to the printing apparatus by verifying the correct identity of a replaceable module before the printing apparatus fully engages the replaceable module.
Many types of printing apparatus, such as office printers and photocopiers, have replaceable modules, such as ink or toner containers, imaging elements, fusers, etc. Some of these modules are designed to be replaced easily by the user, and are sometimes called customer replaceable units (CRU's ). Such customer replaceable units are convenient for machine users. However, inserting an incorrect replaceable module may damage parts of the printing apparatus. For example, inserting into a printing apparatus a toner container having an incorrect toner may cause the printing apparatus to produce poor quality prints, or may even damage components of the printing apparatus.
Physical barriers, such as “keys,” are used to block insertion of an incorrect replaceable module. However, depending on the physical structure of the printing apparatus and associated replaceable module, the number of physical “key” combinations may be limited, which limits the number of incorrect replaceable modules that can be reliably excluded.